Seat cushioning spring device

ABSTRACT

Cushioning spring device for seat structure comprises seat frame having front and rear horizontal members and seat frame line having one end supported by front horizontal member and rear edge arranged with constant space relative to rear horizontal member. Improvement comprises at least two cushioning members located within the space formed by seat members located within the space formed by seat frame line and rear horizontal member. Cushioning members are substantially parallel to rear horizontal member and are connected between seat frame line and rear horizontal member. Improvement also includes spring member stretched between seat frame line and rear horizontal member of seat frame.

United States Patent [72] Inventors Seizho Ohta;

Motokuni Kage, Toyota, Japan [2|] Appl. No. 750,589 [22] Filed Aug. 6,1968 [45] Patented Jan. 19, 1971 [73] Assignee Toyota Jidosha Kogyo Kabushiki Kaisha Toyota, Japan a corporation of Japan [32] Priority Aug. 8, 1967 [3 3] Japan [3 l 42/50825 [54] SEAT CUSHIONING SPRING DEVICE 2 Claims, 4 Drawing Figs.

[52] U.S. Cl 267/107, 267/1 12 [51] Int. Cl ..A47c 23/16, A47c 23/26 [50] Field of Search 267/103,

Primary Examiner-Arthur L. La Point Attorney-Connolly and Hutz ABSTRACT: Cushioning spring device for seat structure comprises seat frame having front and rear horizontal members and seat frame line having one end supported by front horizontal member and rear edge arranged with constant space relative to rear horizontal member. improvement comprises at least two cushioning members located within the space formed by seat members located within the space formed by seat frame line and rear horizontal member. Cushioning members are substantially parallel to rear horizontal member and are connected between seat frame line and rear horizontal member. Improvement also includes spring member stretched between seat frame line and rear horizontal member of seat frame.

PATENTED JAN 1 9 ml sum 1 oF 2 PATENTE'D m1 9 197i 315 551505 sum 2 or 2 SEAT CUSIIIONING SPRING DEVICE BACKGROUND AND SUMMARY OF THE INVENTION The present invention relates to a cushioning spring device for a seat.

One of its objects is to provide asystem that can increase the sitting comfort and the comfortability of the feet of a person sitting on a rear seat. The working principle of the system is as follows. When the human load falls on the seat, the rear edge of the seat is deflected with ample elastic support relative to the seat frame. Meanwhile, as the longitudinal length from the load center of the human body in sitting posture to the rear of the seat frame is designed short, a certain extent of movement in the sitting human body will not displace the rumps, with the sitting contour line being all the time kept ideal thereby improving the sitting comfort and at the same time increasing the vertical space between the back of the front seat and the floor surfacev As a result the comfortability of the feet of a person sitting on a rear seat is assured as his feet are stretched under the front seat.

BRIEF DESCRIPTION OF THE DRAWING Novel features and advantages of the present invention will become apparent to one skilled in the art from a reading of the following detailed description in conjunction with the accompanying drawing wherein similar reference characters refer to similar parts and in which:

FIG. I is a perspective view of a cushioning spring device according to the present invention;

FIG. 2 is a sectional view taken along line 2-2 of FIG. 1;

FIG. 3 is a perspective view of another embodiment of the present invention; and

fig. 4 is a diagrammatic elevational view illustrating the advantages of the present invention.

DETAILED DESCRIPTION OF THE INVENTION In conventional vehicle seats, for example,

In the present invention, the major rear edge of the seat frame line which is composed of zigzag linear spring members stretched in parallel is arranged in parallel with a space to the rear horizontal member end of the cushioning member is fastened to at least two spots inside both sides of the rear edge of the frame line while the other end of the cushioning member is fastened to the rear horizontal member of the seat frame. The cushioning member is arranged in the space defined by the rear horizontal member of the seat frame or the seat frame and the rear edge of the seat frame line. The spring member projects from both sides of the rear edge of the seat frame line. The ends of the spring member are stretched on the frame and between the spring member and the cushioning member of the rear edge of the seat frame line is elastically supported relative to the seat frame against the load resting on the seat.

To explain the composition of the present invention with reference to FIGS. 1-3, in order to constitute the rear edge of the seat cushioning spring device indicated by 1, the seat top 4 is formed by stretching over seat frame line 2 constituting the outer frame in longitudinal or transverse direction of the seat a plurality of zigzag linear spring members 3 in parallel, the spring members being the press-formed, so-called formed spring or the so-called S-springs which are automatically produced and formed by zigzag machinery. The front edge of the linear spring member 3 which forms the seat top 4 is connected to the front member 51 of the seat frame 5. Both sides of the seat frame line 2 and both sides of seat frame 5 are linked elastically by spring members 31 such as zigzag linear springs or coil springs. Next, the major rear edge of the seat frame line 2 on which a plurality of zigzag linear spring members 3 are stretched in parallel is arranged in parallel with a space to the rear horizontal member 52 of the seat frame 5. One end of the cushioning member 7 is attached to a hook 22 provided at the rear edge of the frame line 2 on at least two spots inside both sides 21 of the rear edge of the frame line 2.

The cushioning member 7 can be a coil spring, a torsion spring, an elastic link, or rubber band, for example.

In the embodiment illustrated in FIG. 3, the inward ends of the cushioning member 7 at the two spots are consolidated into a stem 71 to which the projecting part of the linear spring member 3 from the frame line 2 is fastened by a clip 8 and so The outward ends of the cushioning member 7 engage the holes of a flange 9, for example, which is fitted to the rear horizontal member 52 of the seat frame 5. The cushioning member 7 is arranged in the space C containing the gap formed between the back of the seat frame .5 or the rear horizontal member 52 of the seat frame 5 and the rear edge of the seat frame line 2. f.

To both sides 21 of the rear edge of the seat frame line 2 is fastened by a clip 8 one end of the spring member 10 constituted by the projecting pieces from the frame line 2 toward the rear horizontal member 52 of the seat frame 5, for example, a torsion bar. The other end of the spring member 10 is stretched to the back of the rear horizontal member 52 of the frame 5 and fastened with a metal clamp 81.

Moreover, depending on the need, bent portions as shown in FIGS. I and 2 are formed in the spring member 10 at the spot 21 on both sides of the rear edge of the seat frame line 2 to which one end of the spring member 10 is fastened and at the rear horizontal member 52 of the frame 5 to which the other end of the spring member 10 is fastened. At these bent portions a certain gap is provided, if necessary, between the two members to be fastened.

When a human load falls of the surface of a seat equipped with the seat spring system of the present invention, the greater part of his load is carried by the cushioning members 7 each arranged with one end fastened in the space C containing the gap between the rear edge of the frame line 2 stretched with the linear spring members 3 and the rear horizontal member 52 of the seat frame 5. As a result, the cushioning members are fully deflected sidewise and in accordance with the deflection of the cushioning members 7 the spring members 10 projecting from both sides 21 of the rear edge of the seat frame line 2 and stretched to the back of seat frame 5 and deflected with the back as the base while the rear edge of the seat frame line 2 is elastically supported in vertical direction against the human load falling on the seat top. Thus, both the rear edge of the seat frame line 2 and the center of load L on the seat top 4 are sufficiently deflected relative to the back of seat frame 5 in vertical direction and in consequence the seat top assumes an ideal sitting contour curve.

As described above, in a seat equipped according to this invention, when the human load falls on the seat, the rear edge of the seat can be sufficiently deflected elastically relative to the seat frame, while at the same time the longitudinal dimension of the seat from the center of sitting load on the seat surface to the rear of seat frame can be set small. As a result, a certain extent of motion in the sitting human body will not displace the rumps. The ideal sitting contour curve is thereby retained all the time with the sitting comfort vastly improved. Through proper selection of the shapes of cushioning and spring members, the necessary load-deflection characteristics can be easily set.

Moreover, there is no need for bending the rear part of the linear spring member since the back of the cushioning spring device can be designed thin in the vertical direction. The vertical space between the back of the seat and the floor surface can be so enlarged as to assure an increased comfort to the feet of a rear-seat person. Further, the assembling of the seat frame line and the back of seat frame is extremely simplified on account of the cushioning member and spring member and the number of steps involved in the fitting can be drastically reduced in comparison with the conventional system.

Thus, the overall effect of this invention is remarkable.

It should be noted that although the description in this specification refers to vehicle seats, automobile seats in particular, the technical idea underlining the present invention is applicable to all seats in general. The conventional cushioning spring system has the drawback in that the dimension D is understood from FIG. 4, the smaller the dimension D, the more comfortable the sitting posture of the person on the front seat. Also, the larger the dimension S, the greater the comfort given to the feet of the person sitting in the rear.

We claim:

l. A cushioning spring device for a seat comprising a seat frame having a front horizontal member and a rear horizontal member elevated from the front horizontal member, a seat frame line having one end supported by the front horizontal member of the seat frame and a rear edge arranged with a con- 

1. A cushioning spring device for a seat comprising a seat frame having a front horizontal member and a rear horizontal member elevated from the front horizontal member, a seat frame line having one end supported by the front horizontal member of the seat frame and a rear edge arranged with a constant space relative to the elevated rear horizontal member of the seat frame, at least two cushioning members located within the space formed by the seat frame line and the elevated rear horizontal member of the seat frame connected between the seat frame line and the elevated rear horizontal member, each cushioning member extending substantially parallel to the elevated rear horizontal member of the seat frame, and a spring member stretched between the seat frame line and the elevated rear horizontal member.
 2. A device as in claim 1 wherein the cushioning members are coil springs. 